The polyurethane foam industry is well under way replacing the ozone depleting chlorofluorocarbons (CFCs) with more benign compounds such as hydrochlorofluorocarbons (HCFCs). However, HCFCs appear to be a temporary replacement; and efforts continue toward a permanent solution by employing blowing agents that have zero ozone depletion potential.
Hydrocarbons are a class of compounds receiving considerable attention as possible permanent solutions to HCFC-blown foams. Advantages of hydrocarbons include a zero ozone depletion potential, a very low global warming potential, and being liquids at room temperature. Hydrocarbons are also inexpensive when compared to HCFCs or hydrofluoroalkanes (HFAs). In addition, the technology for the safe handling of flammable blowing agents in a manufacturing environment already exists in practice. One major drawback to hydrocarbons, however, is their high degree of inherent flammability.
Insulation foams are closed cell polyurethane and/or polyisocyanurate foams. Such foams have applications in refrigeration cabinets, doors, and in the building construction industry where it is desired to retard as much as possible the flammability of the foam. Since insulation foams are closed cell, the blowing gases are trapped within the cells in the foam. Developing flame resistant insulating foams for the building construction industry is particularly difficult when the foam contains a flammable blowing agent.